Hubble space telescope observations of accretion-induced star formation in the tadpole galaxy Kiso 5639

• Verfasst von: Elmegreen, Debra Meloy [VerfasserIn]
• Verfasst von: Elmegreen, Bruce G. [VerfasserIn]
• Verfasst von: Almeida, Jorge Sánchez [VerfasserIn]
• Verfasst von: Muñoz-Tuñón, Casiana [VerfasserIn]
• Verfasst von: Mendez-Abreu, Jairo [VerfasserIn]
• Verfasst von: Gallagher, John S. [VerfasserIn]
• Verfasst von: Rafelski, Marc [VerfasserIn]
• Verfasst von: Filho, Mercedes [VerfasserIn]
• Verfasst von: Ceverino, Daniel [VerfasserIn]
• Titel: Hubble space telescope observations of accretion-induced star formation in the tadpole galaxy Kiso 5639
• Verf.angabe: Debra Meloy Elmegreen, Bruce G. Elmegreen, Jorge Sánchez Almeida, Casiana Muñoz-Tuñón, Jairo Mendez-Abreu, John S. Gallagher, Marc Rafelski, Mercedes Filho, and Daniel Ceverino
• E-Jahr: 2016
• Jahr: 2016 July 13
• Umfang: 15 S.
• Fussnoten: Gesehen am 06.05.2020
• Titel Quelle: Enthalten in: The astrophysical journal / 1
• Ort Quelle: London : Institute of Physics Publ., 1996
• Jahr Quelle: 2016
• Band/Heft Quelle: 825(2016,2) Artikel-Nummer 145, 15 Seiten
• ISSN Quelle: 1538-4357
• DOI: doi:10.3847/0004-637X/825/2/145
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1697290221

Abstract

The tadpole galaxy Kiso 5639 has a slowly rotating disk with a drop in metallicity at its star-forming head, suggesting that star formation was triggered by the accretion of metal-poor gas. We present multi-wavelength Hubble Space Telescope Wide Field Camera 3 images of UV through I band plus Hα to search for peripheral emission and determine the properties of various regions. The head has a mass in young stars of and an ionization rate of s−1, equivalent to ∼2100 O9-type stars. There are four older star-forming regions in the tail, and an underlying disk with a photometric age of ∼1 Gyr. The mass distribution function of 61 star clusters is a power law with a slope of −1.73 ± 0.51. Fourteen young clusters in the head are more massive than , suggesting a clustering fraction of 30%-45%. Wispy filaments of Hα emission and young stars extend away from the galaxy. Shells and holes in the head H ii region could be from winds and supernovae. Gravity from the disk should limit the expansion of the H ii region, although hot gas might escape through the holes. The star formation surface density determined from Hα in the head is compared to that expected from likely pre-existing and accreted gas. Unless the surface density of the accreted gas is a factor of ∼3 or more larger than what was in the galaxy before, the star formation rate has to exceed the usual Kennicutt-Schmidt rate by a factor of .